/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
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 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
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 */
package com.sun.appserv.management.util.misc;

import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;

public final class IteratorUtil
{
		private
	IteratorUtil( )
	{
		// disallow instantiation
	}
	
	
		public static <T> Object[]
	toArray( final Iterator<T>	iter)
	{
		final List<T> list	= new ArrayList<T>();
		
		while ( iter.hasNext() )
		{
			final T	elem	= iter.next();
			list.add( elem );
		}
		
		final Object[]	result	= new Object[ list.size() ];
		list.toArray( result );
		
		return( ArrayConversion.specializeArray( result ) );
	}
	
    /**
        @param iter 
        @return the Class of the elements, or null if all null or different
     */
		public static Class
	getUniformClass( final Iterator<?> iter)
	{
		Class	theClass	= null;
		
        Object next;
		if ( iter.hasNext() )
		{
            next   = iter.next();
			theClass	= (next == null) ? null : next.getClass();
		}

		while ( iter.hasNext() )
		{
            next    = iter.next();
            
			if ( next != null && next.getClass() != theClass )
			{
				theClass	= null;
				break;
			}
		}
		
		return( theClass );
	}
	
    /**
        @param iter 
        @param theClass
        @param exactMatch  if true, then subclasses are considered to be different
        @return true if all items are of the same class
     */
		public static <T> boolean
	isUniformClass(
		final Iterator<?>	iter,
		final Class<T>      theClass,
		final boolean       exactMatch )
	{
		boolean	isUniform	= true;
		
		while ( iter.hasNext() )
		{
            Object next = iter.next();
			final Class	nextClass	= (next == null) ? null : next.getClass();
			
			if ( nextClass != theClass && nextClass != null )
			{
				if ( exactMatch )
				{
					isUniform	= false;
					break;
				}
				
				if ( ! theClass.isAssignableFrom( nextClass ) )
				{
					isUniform	= false;
					break;
				}
			}
		}
		
		return( isUniform );
	}
}